Lake Huron is one of the five Great Lakes of eastern North America. It separates the U.S. state of Michigan from the Canadian province of Ontario. Georgian Bay, the easternmost part of Lake Huron, is located entirely within Canadian territory. Lake Huron is separated from neighboring Lake Michigan by a narrow channel. The surface of Lake Huron is 579 feet above sea level, and the lake's maximum depth is 750 feet. It covers an area of about 23,000 square miles. Like the other Great Lakes, it is a remnant of the larger Glacial Lake Agassiz, formed by melting ice as the continental glaciers retreated thousands of years ago. Lake Huron is also home to Manitoulin Island, the largest lake island in the world.